Point-to-multipoint traffic engineering (P2MP TE) implements a multicast service by establishing a “tree shape” path (that is, a tunnel) from a head node (that is, an ingress node) to a plurality of tail nodes (that is, egress nodes). It can be learned that path establishment is an indispensable process for implementing the multicast service by the P2MP TE. Currently, a node in the P2MP TE supports the Resource Reservation Protocol (RSVP). Therefore, when a path is established, a head node needs to collect information about all nodes in a P2MP TE network by using a refresh message in the RSVP. When information about a node is changed, the head node needs to notify the changed information to all the nodes in the P2MP TE network by using a refresh message. Such a manner of establishing the P2MP TE makes a path establishment process complex, and is disadvantageous to network management and maintenance.